The Biostatistical Core will be responsible for collecting and maintaining relevant pre- and post-transplant data from consecutive patients enrolled on clinical trials described in projects 3-5. The core will also support data retrieval, analysis and interpretation for these patient groups. The Biostatistical Core will also aid in the design of clinical trials testing hypotheses described in projects 3-5 and, when appropriate, give guidance to basic researchers attempting to plan or interpret laboratory-based projects described in the program project. This Biostatistical Core will assure quality of data collection, and foster a uniform and integrated approach to data interpretation and reporting by clinical and basic research project leaders in the Program Project Grant. The efforts of the Biostatistical Core will be merged with those of the larger, ongoing efforts of the existing University of Minnesota Bone Marrow Transplant Program Biostatistical Facility in an attempt to integrate overall institutional bone marrow transplant clinical research efforts and to promote maximum economy.